Ruby: How to group a Ruby array?

Question

I have a Ruby array

> list = Request.find_all_by_artist(\"Metallica\").map(&:song)
=> [\"Nothing else Matters\", \"Enter sandman\", \"Enter Sandman         


        

Answer 1

As of Ruby 2.7, you can use Enumerable#tally.

list.tally
# => {"Nothing else Matters"=>1, "Enter sandman"=>1, "Enter Sandman"=>1, "Master of Puppets"=>3}